I retouch photos and could digitally repaint your bus so you could check out different colors and what-if-we-left-the-roof-the-sames and such. Ten bucks - and no charge if you're not happy with the work. More than one idea you want to try out? Five bucks each after the first one.
A fellow wanted this pattern and color:
And I produced this (you send me a photo of your bus):
(I also retouch new photos and restore old ones: see examples at Retouching and Restoration - Dapplecreek Retouching & Photo Repair